Aerating simply involves making small, but fairly deep holes through the grass into the soil. The holes allow air, water and essential nutrients to get from the surface into the soil.
You can use a garden fork or this tool
Aeration is an important factor in keeping lawns healthy and helps stop waterlogging.
These are the main benefits of aerating a compacted lawn.
The best time to aerate is during the growing season avoiding very hot weather that makes the soil dry and difficult to penetrate, so early or late spring or autumn are the best times, but anytime (tine) is better than none.
How do I know a Lawn Needs Aerating?
The signs that tell you your lawn needs aeration are not always obvious, but lawns especially on heavy clay soil that get regular heavy use and show wear and tear and thinning, turning brown quickly in dry weather need to be aerated on a regular basis, at least once a year. Or you may have had a visit from Mike the flowerpotman to investigate a lawn drainage problem who to your relief tells you that the lawn is compacted and won't need to be dug up and drainage installed, just aerated.
Your lawn will need aerating if: